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<a name="boost.program_options.variable_value"></a><div class="titlepage"></div>
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<h2><span class="refentrytitle">Class variable_value</span></h2>
<p>boost::program_options::variable_value</p>
</div>
<h2 class="refsynopsisdiv-title">Synopsis</h2>
<div class="refsynopsisdiv"><pre class="synopsis"><span class="comment">// In header: &lt;<a class="link" href="../../program_options/reference.html#header.boost.program_options.variables_map_hpp" title="Header &lt;boost/program_options/variables_map.hpp&gt;">boost/program_options/variables_map.hpp</a>&gt;

</span>
<span class="keyword">class</span> <a class="link" href="variable_value.html" title="Class variable_value">variable_value</a> <span class="special">{</span>
<span class="keyword">public</span><span class="special">:</span>
  <span class="comment">// <a class="link" href="variable_value.html#boost.program_options.variable_valueconstruct-copy-destruct">construct/copy/destruct</a></span>
  <a class="link" href="variable_value.html#id-1_3_30_9_11_1_1_2_4-bb"><span class="identifier">variable_value</span></a><span class="special">(</span><span class="special">)</span><span class="special">;</span>
  <a class="link" href="variable_value.html#id-1_3_30_9_11_1_1_2_5-bb"><span class="identifier">variable_value</span></a><span class="special">(</span><span class="keyword">const</span> <span class="identifier">boost</span><span class="special">::</span><span class="identifier">any</span> <span class="special">&amp;</span><span class="special">,</span> <span class="keyword">bool</span><span class="special">)</span><span class="special">;</span>

  <span class="comment">// <a class="link" href="variable_value.html#id-1_3_30_9_11_1_1_2_2-bb">friend functions</a></span>
  <span class="identifier">BOOST_PROGRAM_OPTIONS_DECL</span> <span class="keyword">void</span> 
  <a class="link" href="variable_value.html#id-1_3_30_9_11_1_1_2_2_1-bb"><span class="identifier">store</span></a><span class="special">(</span><span class="keyword">const</span> <a class="link" href="basic_parsed_options.html" title="Class template basic_parsed_options">basic_parsed_options</a><span class="special">&lt;</span> <span class="keyword">char</span> <span class="special">&gt;</span> <span class="special">&amp;</span><span class="special">,</span> <a class="link" href="variables_map.html" title="Class variables_map">variables_map</a> <span class="special">&amp;</span><span class="special">,</span> <span class="keyword">bool</span><span class="special">)</span><span class="special">;</span>

  <span class="comment">// <a class="link" href="variable_value.html#id-1_3_30_9_11_1_1_2_3-bb">public member functions</a></span>
  <span class="keyword">template</span><span class="special">&lt;</span><span class="keyword">typename</span> T<span class="special">&gt;</span> <span class="keyword">const</span> <span class="identifier">T</span> <span class="special">&amp;</span> <a class="link" href="variable_value.html#id-1_3_30_9_11_1_1_2_3_1-bb"><span class="identifier">as</span></a><span class="special">(</span><span class="special">)</span> <span class="keyword">const</span><span class="special">;</span>
  <span class="keyword">template</span><span class="special">&lt;</span><span class="keyword">typename</span> T<span class="special">&gt;</span> <span class="identifier">T</span> <span class="special">&amp;</span> <a class="link" href="variable_value.html#id-1_3_30_9_11_1_1_2_3_2-bb"><span class="identifier">as</span></a><span class="special">(</span><span class="special">)</span><span class="special">;</span>
  <span class="keyword">bool</span> <a class="link" href="variable_value.html#id-1_3_30_9_11_1_1_2_3_3-bb"><span class="identifier">empty</span></a><span class="special">(</span><span class="special">)</span> <span class="keyword">const</span><span class="special">;</span>
  <span class="keyword">bool</span> <a class="link" href="variable_value.html#id-1_3_30_9_11_1_1_2_3_4-bb"><span class="identifier">defaulted</span></a><span class="special">(</span><span class="special">)</span> <span class="keyword">const</span><span class="special">;</span>
  <span class="keyword">const</span> <span class="identifier">boost</span><span class="special">::</span><span class="identifier">any</span> <span class="special">&amp;</span> <a class="link" href="variable_value.html#id-1_3_30_9_11_1_1_2_3_5-bb"><span class="identifier">value</span></a><span class="special">(</span><span class="special">)</span> <span class="keyword">const</span><span class="special">;</span>
  <span class="identifier">boost</span><span class="special">::</span><span class="identifier">any</span> <span class="special">&amp;</span> <a class="link" href="variable_value.html#id-1_3_30_9_11_1_1_2_3_6-bb"><span class="identifier">value</span></a><span class="special">(</span><span class="special">)</span><span class="special">;</span>
<span class="special">}</span><span class="special">;</span></pre></div>
<div class="refsect1">
<a name="id-1.3.30.9.12.4.4"></a><h2>Description</h2>
<p>Class holding value of option. Contains details about how the value is set and allows to conveniently obtain the value. </p>
<div class="refsect2">
<a name="id-1.3.30.9.12.4.4.3"></a><h3>
<a name="boost.program_options.variable_valueconstruct-copy-destruct"></a><code class="computeroutput">variable_value</code> 
        public
       construct/copy/destruct</h3>
<div class="orderedlist"><ol class="orderedlist" type="1">
<li class="listitem"><pre class="literallayout"><a name="id-1_3_30_9_11_1_1_2_4-bb"></a><span class="identifier">variable_value</span><span class="special">(</span><span class="special">)</span><span class="special">;</span></pre></li>
<li class="listitem"><pre class="literallayout"><a name="id-1_3_30_9_11_1_1_2_5-bb"></a><span class="identifier">variable_value</span><span class="special">(</span><span class="keyword">const</span> <span class="identifier">boost</span><span class="special">::</span><span class="identifier">any</span> <span class="special">&amp;</span> xv<span class="special">,</span> <span class="keyword">bool</span> xdefaulted<span class="special">)</span><span class="special">;</span></pre></li>
</ol></div>
</div>
<div class="refsect2">
<a name="id-1.3.30.9.12.4.4.4"></a><h3>
<a name="id-1_3_30_9_11_1_1_2_2-bb"></a><code class="computeroutput">variable_value</code> friend functions</h3>
<div class="orderedlist"><ol class="orderedlist" type="1"><li class="listitem">
<pre class="literallayout"><span class="identifier">BOOST_PROGRAM_OPTIONS_DECL</span> <span class="keyword">void</span> 
<a name="id-1_3_30_9_11_1_1_2_2_1-bb"></a><span class="identifier">store</span><span class="special">(</span><span class="keyword">const</span> <a class="link" href="basic_parsed_options.html" title="Class template basic_parsed_options">basic_parsed_options</a><span class="special">&lt;</span> <span class="keyword">char</span> <span class="special">&gt;</span> <span class="special">&amp;</span> options<span class="special">,</span> <a class="link" href="variables_map.html" title="Class variables_map">variables_map</a> <span class="special">&amp;</span> m<span class="special">,</span> <span class="keyword">bool</span><span class="special">)</span><span class="special">;</span></pre>
<p>Stores in 'm' all options that are defined in 'options'. If 'm' already has a non-defaulted value of an option, that value is not changed, even if 'options' specify some value. </p>
</li></ol></div>
</div>
<div class="refsect2">
<a name="id-1.3.30.9.12.4.4.5"></a><h3>
<a name="id-1_3_30_9_11_1_1_2_3-bb"></a><code class="computeroutput">variable_value</code> public member functions</h3>
<div class="orderedlist"><ol class="orderedlist" type="1">
<li class="listitem">
<pre class="literallayout"><span class="keyword">template</span><span class="special">&lt;</span><span class="keyword">typename</span> T<span class="special">&gt;</span> <span class="keyword">const</span> <span class="identifier">T</span> <span class="special">&amp;</span> <a name="id-1_3_30_9_11_1_1_2_3_1-bb"></a><span class="identifier">as</span><span class="special">(</span><span class="special">)</span> <span class="keyword">const</span><span class="special">;</span></pre>
<p>If stored value if of type T, returns that value. Otherwise, throws boost::bad_any_cast exception. </p>
</li>
<li class="listitem">
<pre class="literallayout"><span class="keyword">template</span><span class="special">&lt;</span><span class="keyword">typename</span> T<span class="special">&gt;</span> <span class="identifier">T</span> <span class="special">&amp;</span> <a name="id-1_3_30_9_11_1_1_2_3_2-bb"></a><span class="identifier">as</span><span class="special">(</span><span class="special">)</span><span class="special">;</span></pre>
<p>This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts. </p>
</li>
<li class="listitem">
<pre class="literallayout"><span class="keyword">bool</span> <a name="id-1_3_30_9_11_1_1_2_3_3-bb"></a><span class="identifier">empty</span><span class="special">(</span><span class="special">)</span> <span class="keyword">const</span><span class="special">;</span></pre>Returns true if no value is stored. </li>
<li class="listitem">
<pre class="literallayout"><span class="keyword">bool</span> <a name="id-1_3_30_9_11_1_1_2_3_4-bb"></a><span class="identifier">defaulted</span><span class="special">(</span><span class="special">)</span> <span class="keyword">const</span><span class="special">;</span></pre>
<p>Returns true if the value was not explicitly given, but has default value. </p>
</li>
<li class="listitem">
<pre class="literallayout"><span class="keyword">const</span> <span class="identifier">boost</span><span class="special">::</span><span class="identifier">any</span> <span class="special">&amp;</span> <a name="id-1_3_30_9_11_1_1_2_3_5-bb"></a><span class="identifier">value</span><span class="special">(</span><span class="special">)</span> <span class="keyword">const</span><span class="special">;</span></pre>
<p>Returns the contained value. </p>
</li>
<li class="listitem">
<pre class="literallayout"><span class="identifier">boost</span><span class="special">::</span><span class="identifier">any</span> <span class="special">&amp;</span> <a name="id-1_3_30_9_11_1_1_2_3_6-bb"></a><span class="identifier">value</span><span class="special">(</span><span class="special">)</span><span class="special">;</span></pre>
<p>Returns the contained value. </p>
</li>
</ol></div>
</div>
</div>
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<div class="copyright-footer">Copyright © 2002-2004 Vladimir Prus<p>Distributed under the Boost Software License, Version 1.0.
      (See accompanying file <code class="filename">LICENSE_1_0.txt</code> or copy at 
      <a href="http://www.boost.org/LICENSE_1_0.txt" target="_top">http://www.boost.org/LICENSE_1_0.txt</a>)
      </p>
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